Hi guys, this is related to Device Hub. Yes, exactly!
So, -the only one- solution is:
1) Reset your phone (required)
2) When resetting is completed, complete your installation steps
3) When the phone is ready to use, quickly go to Settings > Date+Time
4) Set the year like 2150 or more
5) Go to Settings, tap the Device Hub
6) Uninstall it
7) Set the date as auto again
Problem will be solved.
Never open Device Hub even once! Uninstall it and don't install again.
p.s. If you open Device Hub even once, battery saver crashes and your issue comes over again. Then you must reset your phone to solve it.
If you open Device Hub once, uninstalling it will not solve this issue. You will have to reset your phones...